Ventilated contact points



Nov. 10, 1964 R. H. HIEGER VENTILATED CONTACT POINTS Filed Feb. 24, 1964 x A w w l i/e5 /ae IN VEN TOR Roamr HENRY H/saen A m n. H 5 a 5 m H a A TTGRNEVS United States Patent ()6 ice 3,156,791 VENTILATED CONTACT POINTS Robert Henry Hieger, 14395 Faust, Detroit, Mich. Filed Feb. 24, 1964, Ser. No. 347,649 6 Claims. (Cl. 206-30) The present invention is a continuation in part of my co-pending application SN. 793,126, filed February 13, 1959, and now abandoned, and relates to new and useful improvements in contact points and more particularly contact points for heavy duty make and break circuits, suchas in an automobile ignition system. While the invention is directed to automobile ignition systems, it must be understood that the invention is applicable to trucks, busses, aircraft, boats, lawnmowers and the like or any other device using an internal combustion engine which requires an ignition system.

The invention deals with the mating surfaces of two cooperating contacts of the type used in a distributor for an automobile ignition circuit. A first contact is carried on a movable arm and a second contact is carried on a stationary breaker arm. The contacts are periodically moved into and out of engagement by a rotating cam element in the distributor, which acts on the movable arm. The purpose of this invention is to prolong the life of these contacts. This is accomplished by the provision of an arcuate cross sectional slot in the surface of at least one of the contacts, the slot extending across the contact surface so as to substantially intersect the center thereof. In accordance with the invention, the slot forms a passageway Which promotes the circulation of air between the contact surfaces. The increased circulation of air in the arcuate cross sectional slot ventilates the contact surfaces, which resul s in a consequent reduction of heating, as well as oxidation. The arcuate cross sectional passageway further aids in the elimination of metal dust which results from contact wear. This is accomplished by mounting the slotted contact so that the slot therein is disposed diagonally to the body of the bracket carried by the stationary breaker arm, upon which the first contact is mounted. The metal dust caused by wear is removed through the passageway by the inherent vibration of the distributor and the circulating air.

Throughout the years, ignition contact points have been acceptable if they would perform efiiciently for approximately 10,000 miles of driving. After this time, the pitting caused by heat, oxidation and resultant wear usually made replacement necessary. Replacement of the contact, as simple as it is, necessitates the vehicle in I which they are located to be taken out of service. This is objectionable, not only to persons in business, but also to the motorist who uses his automobile only for pleasure. Therefore, extending the life of these contacts will not only eliminate a portion of this down time when the vehicle is out of service, but it will also represent a cost savings which results from less frequent replacement of the contacts and the overall elliciency of operation.

It is a principal object of the present invention to provide a set of contacts which will have a substantially greater life expectancy than those contacts which are currently available, without an appreciable increase in cost.

Another object of the invention is the provision of a set of contact points which are ventilated and air cooled through at least one slot which extends diagonally across one generally flat surface of the contact, the slot therein being of less dimension at the center than the ends, the cross-section of the slot being generally arcuate.

These and other objects of the invention can be accomplished by the provision of a set of contacts for an automobile ignition circuit wherein a first diagonal slot of 3,156,791 Patented Nov. 10, 1964 arcuate cross section is located in the surface of one of said contacts and a second diagonal slot of arcuate cross section is located in the surface of said contact, said arcuate cross section slots extending across the entire face of said contact; an angle bracket, said angle bracket having a body portion; a tab on said angle bracket, said tab disposed at generally right angles to the body portion thereof; a pivotal breaker arm affixed in parallel relationship to the body and perpendicular to said angle bracket; the first contact secured to the tab on said angle bracket, the second contact secured to said pivotal breaker arm, said first and second contacts adapted for engagement with each other; the arcuate cross sectional slots in said contact disposed at substantially to each other and in generally diagonal relationship to the body of said angle bracket; the making and breaking of the ignition circuit during operation induces the flow of air between the contact faces, the opening of said contacts draws air in, while the closin of the contacts compresses the air therebetween the contacts to expel the air, and any metal dust which may be present, thereby reducing the heating, oxidation and pitting of the contacts.

Other objects of this invention will appear in the following description and appended claims, reference being bad to the accompanying drawings which form a part of this specification, wherein like reference characters designate corresponding parts in the several views.

In the drawings:

FIGURE 1 illustrates an enlarged perspective view of a single contact which embodies the present invention.

FIGURE 2 shows a plan view of a distributor with the cap removed and a set of contact points which embody the present invention installed therein.

FIGURE 3 illustrates a perspective view of a set of contact points which employ the present invention.

PEGURE 4 is a cross sectional view of a modified contact.

FIGURE 5 illustrates a plan view of a modified contact having a single arcuate cross sectional slot therein.

FIGURE 6 shows an elevational view of a contact set wherein a single arcuate cross sectional slot is provided in each contact.

Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

FIGURE 1 of the drawings illustrates a perspective view of a rivet type contact 10, which embodies the present invention. The flat contact disc 12 may be made of any material such as silver, tungsten or platinum, while the stem 16 of the rivet 14 can be made from some less expensive material and brazed or otherwise secured to the contact disc. In the present instance, the rivet 14 is shown flanged, the flange 18 being of the same outside diameter as the contact disc 12. The top surface of the contact disc is identified by the numeral Ztl and is generally parallel with the lower surface 22 thereof. In addi tion, the top surface 24 of the flanged rivet 14 is parallel to the underside 22 of the contact disc 12, to which it is secured, w lo the stern portion 16 thereof is perpendicular thereto. While the contact disc 12 is shown secured to a flanged rivet 14, the contact disc 12 could of course be secured to any flat conductive surface.

A pair of arcuate cross section slots 26 and 28 extend generally diagonal of the top surface 29 of the contact disc 12, intersecting at the center thereof. The intersec- 3 tion of the slots 26 and 28 occurs at substantially right angles to each other. While it has been felt that the above described slots could be of rectangular, square or triangular cross section, experimentation has shown that with the use of such cross sectional configurations, foreign material in the form of metal dust collects in the corners, the build up of which retards, if not prevents the exhausting of the metal dust the slots are designed to remove. When the arcuate or semi-circular cross section slots of the present invention are used, no corners in which to collect the metal dust are present and therefore the above described problem is non-existent.

FIGURE 2 of the drawings shows a distributor with the cap removed and a set of contact points which embody the present invention installed therein. A similar set of contact points is shown in FIGURE 3 with the contacts in the open position. The rivet contact point lltl shown in FIGURE 1 is positioned in an angle bracket 46 and riveted over as indicated at 15. Should a single fiat disc have been used, it would have to be positioned and brazed or silver soldered to the angle bracket 4th. The upper contact disc 56 on the breaker arm 52 is similar to the lower contact disc 12, however, the surface thereof is flat and is secured to the breaker arm by any suitable means.

While the applicant has shown the arcuate slots in contact disc 12 positioned on the angle bracket, it would be possible to position the slotted disc 12 on the movable breaker arm 52 and secure the flat surface disc as to the angle bracket. It is also conceivable that a single arcuate cross section slot (A) could be placed in each of the contact discs 12 and 50. Each of the slots would of course be located at substantially right angles to each other and would substantially intersect the center of the contact discs (see FIGURE 6).

In FIGURE 3 of the drawings, the positioning of the slots 26 and 28 with respect to the angle bracket to is illustrated. Each arcuate cross sectional slot is so disposed as to lie in substantially diagonal relationship to the angle bracket tab 27 on which the contact disc 12, is mounted. By so positioning, the arcuate cross section slots 26 and 82 form an effective passageway for the elimination of the metal dust which occurs as a result of wear. As the breaker arm 52 moves back and forth, air is drawn between the contact surfaces. The opening of the contacts 12 and so induces the flow of air between the contact surfaces, while the closing of the contacts compresses the air therebetween to expel the air and any metal dust which may be present, thereby reducing the heating, oxidation and pitting of the contact discs. As the breaker arm 52 moves back and forth, the inherent vibration of the distributor as causes any metal dust resulting from Wear to find its way to the arcuate cross section {slots 26 and 28, which is thereafter moved to the fiat body portion 29 of the angle bracket 44? through the compression and circulation of air through the arcuate cross sectional slots.

In the modified contact disc 110 shown in FIGURE 4 of the drawings, the arcuate cross section slots 126 and 128 are disposed at substantially right angles to each other in the manner previously described in connection with FIGURE 1. However, in this contact disc, the intersection of the cross slots is of somewhat lesser dimension than is the depth of the slots at the circumference of the disc. This in turn tends to increase the velocity of the air at the center of the contact and acts to remove the metal dust resulting from wear more effectively. This also affords more efficient cooling of the contact surfaces about the central portion thereof. The contact disc 112 has a flat upper surface 120 and a flat lower surface 122 in generally parallel relationship thereto. While the arcuate cross section slots 126 and 128 are illustrated as being depressed in the center, and extending downwardl therefrom, the slot could effectively be of the same depth throughout its travfirse, Whi e being wider at each edge.

From the foregoing description, it will be apparent that the ventilated contacts of the present invention is simple and efiicient. The cost of manufacture is not appreciably increased, while the utility and life expectancy of the resulting product is enhanced substantially. The metal dust which occurs from wear and ordinarily causes pitting and general breakdown of the contact points is efficiently and quickly removed, thereby rendering the contact set of the present invention less likely to deteriorate as a result of the problems previously encountered.

Having thus described my invention, 1 claim:

1. In a set of contact points for use in the electric ignition circuit of an automotive vehicle, the combination of,

a pair of contacts;

a first diagonal slot of arcuate cross section in the surface of one of said contacts, a second diagonal slot of arcuate cross section in the surface of said contact, said slots extending across the entire surface of said contact;

an angle bracket, said angle bracket having a flat body portion;

a tab on said angle bracket, extending at generally right angles to the body portion thereof;

a pivotal breaker arm affixed in parallel relationship to the flat body of said angle bracket;

the first contact secured to the tab on said angle bracket, the second contact secured to said pivotal breaker arm, said first and second contacts adapted for engagement with each other;

the arcuate cross section slots in said contact disposed at substantially to each other and in generally diagonal relationship to the body of said. angle bracket;

the making and breaking of the ignition circuit during operation induces the flow of air between the contact faces, the opening of said contacts draws air in, while the closing of the contacts compresses the air therebetween the contacts to expel the air, and any metal dust which may be present, thereby reducing the heating, oxidation and pitting of the contacts.

2. A device as in claim 1, wherein said arcuate cross sectional slots are formed in the same contact, said slots being of uniform depth and wider at the outside circumferential edge.

3. A device as in claim 2, wherein the contact having the arcuate cross section slots therein are positioned on the right angle tab of said angle bracket in alignment with the adjacent contact on said pivotal breaker arm.

4. A device as in claim 2, wherein the contact having the arcuate cross section slots therein is positioned in the pivotal breaker arm, in alignment with the adjacent contact on the tab of said angle bracket.

5. In a contact for use in an electric ignition circuit, the combination of,

two adjacent contact discs;

at least one diagonal slot in one of said contact discs;

said diagonal slot being of arcuate cross section;

said arcuate cross section slot being of somewhat less depth at the center than at the circumference and extending toward the edges of the disc; 7

the make and break of said ignition circuit inducing air flow between said contact discs, the velocity of said air being greater at the center of the contact disc than at the circumference thereof, for the effective removal of metal dust resulting from wear.

6. A pair of cooperating ignition contacts for an automotive ignition circuit including a mounting bracket having a substantially right angled cantilevered tab extending therefrom and a pivoted breaker arm pivotally secured to said mounting bracket;

one of said pair of ignition contacts being non-rotatably secured to said cantilevered tab, the other secured to said pivotal breaker arm for facewise engagement 5: r: Q12 a with the respective circular exposed contact faces, from the engaging circular faces of said pair of conone of which has a pair of intersecting and diamettacts. rically extending arcuate cross sectional slots formed References Cited by the Examiner therein and lying normal to each other; NFC T said slotted contact being rotationally oriented so that 5 2 3 U Aubs PATENTS the arcuate cross sectional slots lie diagonally to 32 1/44 Klght 20019 the mounting bracket, whereby the circulation of 5 23% 3 et a1 v r err air between the contacts and the inherent vibration 2,565,373 8/51 Kight 200-166 of said mounting bracket during operation Will efiect the gravitational removal of the foreign particles 10 BERNARD A. GILHEANY, Primary Examiner. 

6. A PAIR OF COOPERATING IGNITION CONTACTS FOR AN AUTOMOTIVE IGNITION CIRCUIT INCLUDING A MOUNTING BRACKET HAV- G ING A SUBSTANTIALLY RIGHT ANGLED CANTILEVERED TAB EXTENDING THEREFROM AND A PIVOTED BREAKER ARM PIVOTALLY SECURED TO SAID MOUNTING BRACKET; ONE OF SAID PAIR OF IGNITION CONTACTS BEING NON-ROTATABLY SECURED TO SAID CANTILEVERED TAB, THE OTHER SECURED TO SAID PIVOTAL BREAKER ARM FOR FACEWISE ENGAGEMENT WITH THE RESPECTIVE CIRCULAR EXPOSED CONTACT FACES, ONE OF WHICH HAS A PAIR OF INTERSECTING AND DIAMETRICALLY EXTENDING ARCUATE CROSS SECTIONAL SLOTS FORMED THEREIN AND LYING NORMAL TO EACH OTHER; SAID SLOTTED CONTACT BEING ROTATIONALLY ORIENTED SO THAT THE ARCUATE CROSS SECTIONAL SLOTS LIE DIAGONALLY TO THE MOUNTING BRACKET, WHEREBY THE CIRCULATION OF AIR BETWEEN THE CONTACTS AND THE INHERENT VIBRATION OF SAID MOUNTING BRACKET DURING OPERATION WILL EFFECT THE GRAVITATIONAL REMOVAL OF THE FOREIGN PARTICLES FROM THE ENGAGING CIRCULAR FACES OF SAID PAIR OF CONTACTS. 